The article deals with axial-symmetric subsonic air-to air ejector with a diffuser adapted for boundary layer suction. The diffuser, which is placed after the mixing chamber of the ejector, has a high divergence angle and is therefore inefficient. To increase efficiency, the diffuser is equipped with a slot enabling boundary layer suction. The effect of boundary layer suction on the airflow in the ejector was measured, as were the static pressure distribution on the mixing chamber wall and ejector characteristics. Both diffuser and ejector efficiency were calculated. Although the efficiency of the diffuser was increased, the efficiency of the ejector itself remained low. and Obsahuje seznam literatury
Open area rainfall and throughfall measurements in the Western Tatra Mountains (altitude about 1500 m a.s.l.) made by tipping bucket gauges were used to estimate the usefulness of the short-time data in analysis of spruce interception. The 10-minute data from period 13 May-13 October 2009 did not reveal meaningful correlations between the open area rainfall and throughfall. Aggregated measurements representing individual rainfall events were more useful. They showed linear relationship between open area rainfall and throughfall for events with total rainfall depth in the open area exceeding 5 mm. Correlation between open area rainfall and throughfall for rainfall events with duration above 120 minutes was significantly better than for the shorter ones. Mean values of interception (percentage of open area rainfall which did not appear in throughfall) of individual rainfall events was high. When we excluded events for which throughfall was higher than the open area rainfall, mean interception for larger and longer rainfall events was 46% and 48%, respectively. For smaller (runoff depth below 5 mm) and shorter events (duration below 2 hours) the mean interception was 70% and 72%, respectively. However, the data revealed very high variability of interception. and Príspevok sa zaoberá hodnotením užitočnosti krátkodobých meraní zrážok na otvorenej ploche a v smrekovom lese pri určovaní intercepcie. Vychádza z merania zrážok preklápacími zrážkomermi v Západných Tatrách v nadmorskej výške okolo 1500 m n.m. Desaťminútové údaje merané v období 13.5.- 13.10.2009 neposkytli použiteľné korelácie medzi dažďom na otvorenej ploche a v lese. Lepšie výsledky boli získané pre sumárne úhrny zrážok pre jednotlivé dažde. Ak úhrn dažďa na voľnej ploche prekročil približne 5 mm, veľkosť podkorunových zrážok rástla lineárne s veľkosťou zrážok na voľnej ploche. Korelácia medzi zrážkami na voľnej ploche a v lese pre dažde s dĺžkou trvania nad 120 minút bola podstatne lepšia, ako pre kratšie dažde. Priemerná hodnota intercepcie (vyjadrenej ako percento zrážok na voľnej ploche, ktoré sa neobjavilo v lese) pre jednotlivé zrážkové udalosti bola vysoká. Po vylúčení udalostí, pre ktoré bol v lese nameraný vyšší úhrn zrážok ako na voľnej ploche, bola priemerná intercepcia pre väčšie dažďe 46 % a pre dlhšie dažde 48 %. Pre menšie (úhrn pod 5 mm) a kratšie (trvanie pod 2 hodiny) dažde bola priemerná intercepcia 70 % a 72%. Hodnoty intercepcie pre jednotlivé udalosti však mali veľkú variabilitu.